Francis Anonia, 43, of Allentown, is accused of recording a student changing clothes during rehearsals and performances.
The school superintendent sent out an email to parents this week saying the board was made aware of the allegations last April.
He was placed on administrative leave and then resigned in June.
"To have a teacher who's supposed to nurture you and to take care of you, especially in what should be a safe place, which is a theatre, to be taken advantage of in that way is really disgusting," said Reese Diaz, a 2018 Parkland High School graduate.
Anonia's phone was seized by Allentown police on February 23, 2023, in connection with an unrelated child pornography case involving his fiancé.
Investigators say his phone was never analyzed since he was not suspected or charged with any crime. But Anonia reportedly never requested his phone back and it was later searched in April 2024 after a student came forward, alleging Anonia had inappropriate contact with him in 2022. That case is still being investigated.
Investigators say five secretly recorded videos of a student were found on the phone.
Superintendent Dr. Mark Madson called the allegations "shocking, disturbing, and inexcusable."
Shortly after the superintendent addressed the situation during Tuesday's school board meeting, parents lodged anger and frustration in his direction.
"I am here looking you directly in the eye and I am calling for your resignation," said parent, Lauren Vargas.
Board members defended the superintendent and this district's actions.
Anonia is currently behind bars on $50,000 bail.
His hearing is scheduled for October 21.